Currently, surface texturing is done via machining, embossing, chemical etching, or laser ablation. Machining entails removal of material from a substrate to leave a desired geometry. One example surface texture creation by micro-machining is the use of a turning operation along with a micro-positioning system [1]. This method allows for accurate shapes and tolerances, but is fairly time consuming and expensive. It could also results in an undesirable residual stress in the workpiece.
Embossing techniques use dies to plastically deform the surface of the material, creating an array of surface features with one punching action. This method is widely used, though the material choices are generally limited to polymers and ductile metals and die wear can be a problem [2-5]. The embossing die is usually made through a chemical etching technique.
Chemical etching involves time-consuming steps, including the use of an etching mask placed directly on the specimen so that the surface can be selectively etched via etching chemicals. Since the mask is generally consumed during the etching step, a new mask must be created for each sample to be textured. This technique is widely used in the laboratory [6, 7], though it is somewhat impractical for industrial applications. Recently, several methods have been developed where the etching mask may be re-used, thereby increasing the efficiency of the process [8, 9].
Laser surface texturing techniques have become popular because they can achieve submicron-sized features in hardened metallic surfaces with highly variable geometries. Recently, this method has been used on a variety of automotive components, mechanical seals, and bearings [10-15]. Laser texturing has also been used to overcome stiction problems with hard disk drives [16, 17]. However, laser texturing does not allow for accurate control over the resulting dimple geometry, and the surface finish is generally poor [18] if a fast process is desired.